The Houston Fire Department is investigating an attempted arson at a southwest Houston mosque after masked men allegedly used gasoline to try to ignite the facility early Saturday.

Surveillance cameras at Madrasah Islamiah, at 6665 Bintliff, captured images of group of at least three men in masks holding canisters and walking toward the back of the mosque, said Atif Fattah, a volunteer at the facility.

Prayer rugs at the back of the mosque were doused with gasoline, Fattah said.

But neither the building nor a brick wall along the back of the mosque caught fire, Fattah said.

The fire appeared to be small and smoke triggered an automatic alarm to fire officials, he said. When firefighters arrived, they saw evidence of a building fire and called the department's arson unit, he said.